Offset document pick-up device

ABSTRACT

A flexural document pick-up device includes: a feeding path comprised of a upper wall and a lower wall; a input tray arranged upstream to the feeding path; a paper feeding unit arranged partially in the feeding path; a separation roller disposed on the opposite side of the paper feeding unit; a blocking arm disposed upstream to the paper feeding unit; a securing groove arranged on the upper wall; and a guiding unit with the following portions disposed sequentially from downstream to upstream of the feeding direction: a securing section which is secured to the securing groove, a flexure section which is extended from the securing section to the feeding path, a guiding section which is connected to the flexure section and essentially parallel to the feeding path, a lifting section which is connected to the guiding section and a vertex which is arranged on the end of the lifting section.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a document pick-up device, in particular to a flexural document pick-up device which is able to avoid paper damage caused by paper warpage.

2. The Related Art

Referring to FIG. 1, the pick-up unit is placed at the entrance of the automatic document feeder for separating the stacked paper and feeding the paper one by one. In order to avoid overlapping the paper, the pick-up unit includes a feeding path, a document pick-up device 20′, a separation device 30′, and a blocking device 40′ disposed between the document pick-up device 20′ and the separation device 30′. Wherein, the blocking device 40′ is arranged in the feeding path to stop paper from entering the feeding path, the document pick-up device 20′ contacts the paper stack to feed the paper into the feeding path, and the separation device 30′ provides friction to the fed paper for stopping the overlapped paper.

However, the paper may be damaged due to the warpage of the paper during the separation process, the conditions that cause the warpage of the paper are shown in FIG. 2 to FIG. 4.

In FIG. 2, the upper paper is free to fall when the lower paper is fed into the feeding path, and thus causing a slight warpage of the leading edge of the upper paper.

In FIG. 3, the separation device 30′ rotates in the direction of feeding the paper back to the input tray for enhancing the effect of the separating the overlapped paper, so the leading end of the paper that contacts with the separation device 30′ is easy warped by the involvement of the separation roller.

In FIG. 4, the separation device 30′ is made of an elastic material to improve the feeding force applied to the paper, so the separation roller will deform under the pulling of the paper during the feeding process and rebound after the paper leaves. However, the rebound of the separation roller also causes warpage of following paper.

Therefore, it is necessary to provide a flexural document pick-up device which is able to guide paper and avoid paper damage caused by paper warpage.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a pick-up device, particular to a pick-up device which is able to avoid paper damage caused by paper warpage.

To achieve said objective, the flexural document pick-up device includes: a feeding path comprised of a upper wall and a lower wall; a input tray arranged at the upstream of the feeding path; a paper feeding unit arranged partially in the feeding path; a separation roller disposed on the opposite side of the paper feeding unit to be contacted with the paper feeding unit; a blocking arm disposed between the input tray and the paper feeding unit and configured to be switchable move between a blocking position for blocking the paper and a feeding position for passing the paper through the feeding path; a securing groove arranged on the upper wall; and a guiding unit with the following portions disposed sequentially from downstream to upstream of the paper feed direction: a securing section which is secured to the securing groove, a flexure section which is extended from the securing section to the feeding path, a guiding section which is connected to the flexure section and essentially parallel to the feeding path, a lifting section which is connected to the guiding section and a vertex which is arranged on the end of the lifting section; wherein the guiding section is movably arranged is a seam space formed with the paper feeding unit and the separation roller, the radius of a virtual circle formed by the separation roller and the lifting section is greater than the wheel diameter of the separation roller, and the vertical distance between the lower wall and the guiding section is greater than the vertical distance between the lower wall fed and the separation roller.

In a preferred embodiment, the junction point of the guiding section and the lifting section is arranged upstream to contact point of the separation roller and the paper.

In a preferred embodiment, the lifting section is arranged downstream to the blocking arm in the paper feed direction.

In a preferred embodiment, the angle between the guiding section and the feeding path is smaller than the angle between the lifting section and the feeding path when viewed from an axial direction of the separation roller.

In a preferred embodiment, the blocking arm is arranged upstream to the vertex.

In a preferred embodiment, the vertical distance between the paper to be fed and the vertex is greater than the vertical distance between the paper to be fed and the bottom of the blocking arm.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following description, with reference to the attached drawings, in which:

FIG. 1 is a side view of a conventional document pick-up unit;

FIG. 2 is a schematic diagram showing the warpage caused by the falling of the paper in the conventional document pick-up unit;

FIG. 3 is a schematic diagram showing the warpage caused by the reversal of the separation roller in the conventional document pick-up unit;

FIG. 4 is a schematic diagram showing the warpage caused by the rebound of the separation roller in the conventional document pick-up unit;

FIG. 5A is a side view of the document pick-up device of the present invention;

FIG. 5B is a side view of lifted blocking arm in the present creation;

FIG. 6 is a side view of the guiding unit;

FIG. 7 is a side view of the guiding unit and the blocking arm;

FIG. 8 is a perspective view of the guiding unit;

FIG. 9A is a side view of the guiding unit and the separation roller in the present invention;

FIG. 9B is an enlarged view of part A of FIG. 9A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to explain in detail, the technical content, structural features, objectives and effects of the present invention, the following is a detailed description with reference to the drawings.

Referring to FIG. 5 to FIG. 8, a flexural document pick-up device 10 of the present invention is disposed between a input tray 11 and a feeding path 12 for feeding the paper stacked in the input tray 11 into the feeding path 12, and the feeding path 12 is comprised of an upper wall 12 a, a lower wall 12 b and a securing groove 13 arranged on the upper wall 12 a. The flexural document pick-up device 10 includes the following components which are disposed from upstream to downstream of the feeding path 12: a blocking arm 40, a guiding unit 50 secured in the securing groove 13, a paper feeding unit 20 partially arranged in the feeding path 12 and a separation roller 30 disposed on the opposite sides of the paper feeding unit 20 for being contacted with the paper feeding unit 20. For convenience of explanation, the terms “upstream” and “downstream” as used hereinafter refers to the direction in which the paper is fed from and the direction in which the paper is fed toward.

The blocking arm 40 is disposed to be movable in a direction perpendicular to the feeding path 12 for switching between a blocking position for blocking the paper and a feeding position for feeding the paper through the feeding path 12. The guiding unit 50 is movably connected in the feeding path 12, thereby guiding the paper to smoothly contact with the paper feeding unit 20.

Referring to FIG. 5 to FIG. 8, the guiding unit 50 comprises a securing section 51, a flexure section 52, a guiding section 53, a lifting section 54 and a vertex 55 which are disposed sequentially from downstream to upstream of the feeding direction. The securing section 51 secured in the securing groove 13. The flexure section 52 is extended from the securing section 51 to the feeding path 12. The guiding section 53 is connected to the flexure section 52 and essentially paralleled to the feeding path 12, the guiding section 53 is arranged between the seam space 21 formed by the paper feeding unit 20 and the separation roller 30. The lifting section 54 is connected to the guiding section 53, and the vertex 55 is arranged at the end of the lifting section 54. Wherein, the securing section 51 will bend while the lifting section 54 contacts with the paper to be fed to guide the paper passing through the paper feeding unit 20 smoothly.

Referring to FIG. 8, the securing groove 13 includes a clamping section 13 a extended toward the feeding path 12 and a fixing hole 13 b which is arranged at the end of the clamping section 13 a and perpendicular to the clamping section 13 a. The guiding unit 50 is bent with a single metal wire and formed into a bilateral symmetry shape. The securing section 51 includes two symmetrical clamping rod 51 a and two fixing rod 51 b which is arranged at the end of the clamping rod 51 a. By clamping the clamping rod 51 a in the clamping section 13 a and securing the fixing rod 51 b in the fixing hole 13 b, the guiding unit 50 is secured on the feeding path 12.

Referring to FIG. 6, FIG. 9A and FIG. 9B, the guiding unit 50 is disposed in a seam space 21 formed by the paper feeding unit 20 and the separation roller 30, and the guiding section 53 forms a slight angle θ 1 with the feeding path 12 for guiding the paper to contact with the paper feeding unit 20, and a junction point (A) (the point where the curvature changes the most) is formed at the turning area between the guiding section 53 and the lifting section 54. In order to ensure the paper to contact with the paper feeding unit 20 smoothly, the contact point E of the separation roller 30 and the paper is disposed downstream to the junction point A, and the vertical distance D1 from the paper to be fed to the guiding section 53 is greater than the vertical distance D2 from the paper to be fed to the separation roller 30.

The lifting section 54 is disposed downstream to the blocking arm 40 in the paper feeding direction, the radius (DS1) of the virtual circle which is co-axis with the separation roller 30 and passes through the lifting section 54 is larger than the radius (DS) of the separation roller 30, and the lifting section 54 forms an angle θ 2 with the feeding path 12. The angle θ 2 is greater than the angle θ 1, so when the paper to be fed passes through the blocking arm 40 and comes in contact with the lifting section 54, more normal force is applied to the lifting section 54, thereby generates a force that pushes the guiding unit 50 away from the feeding path 12.

Referring FIG. 6 and FIG. 7, the vertex 55 is substantially coincided with the blocking arm 40 during the feeding process, the contact point (C) of the paper to be fed and the blocking arm 40 is arranged upstream to the vertex 55. Furthermore, the distance between the vertex 55 and the paper is greater than the distance between the bottom end of the blocking arm 40 and the paper. Therefore, it prevents the paper to be fed from contacting with the separation roller 30 too early during the feeding process, and a gap which may cause the paper to be fed doesn't contact with the lifting section 54 and the guiding section 53 in sequence during the feeding process appeared between the guiding unit 50 and the blocking arm 40. 

What is claimed is:
 1. A flexural document pick-up device includes: a feeding path comprised of an upper wall and a lower wall; an input tray arranged at the upstream of the feeding path; a paper feeding unit arranged partially in the feeding path; a separation roller disposed on the opposite side of the paper feeding unit to be contacted with the paper feeding unit; a blocking arm disposed between the input tray and the paper feeding unit and configured to be switchable move between a blocking position for blocking the paper and a feeding position for passing the paper through the feeding path; a securing groove arranged on the upper wall; and a guiding unit with the following portions disposed sequentially from downstream to upstream of the feeding direction: a securing section which is secured to the securing groove, a flexure section which is extended from the securing section to the feeding path, a guiding section which is connected to the flexure section and essentially parallel to the feeding path, a lifting section which is connected to the guiding section and a vertex which is arranged on the end of the lifting section; wherein the guiding section is movably arranged is a seam space formed with the paper feeding unit and the separation roller, the radius of a virtual circle formed by the separation roller and the lifting section is greater than the wheel diameter of the separation roller, and the vertical distance between the lower wall and the guiding section is greater than the vertical distance between the lower wall and the separation roller.
 2. The flexural document pick-up device as claimed in claim 1, wherein the junction point of the guiding section and the lifting section is arranged upstream to contact point of the separation roller and the paper.
 3. The flexural document pick-up device as claimed in claim 1, wherein the lifting section is arranged downstream to the blocking arm in the paper feed direction.
 4. The flexural document pick-up device as claimed in claim 1, wherein the angle between the guiding section and the feeding path is smaller than the angle between the lifting section and the feeding path when viewed from an axial direction of the separation roller.
 5. The flexural document pick-up device as claimed in claim 1, wherein the blocking arm is arranged upstream to the vertex.
 6. The flexural document pick-up device as claimed in claim 1, wherein the vertical distance between the paper to be fed and the vertex is greater than the vertical distance between the paper to be fed and the bottom of the blocking arm. 